demoralize

v. t. [ imp. & p. p. Demoralized p. pr. & vb. n. Demoralizing. ] [ F. démoraliser; pref. dé- (L. dis- or de) + moraliser. See Moralize. ] To corrupt or undermine in morals; to destroy or lessen the effect of moral principles on; to render corrupt or untrustworthy in morals, in discipline, in courage, spirit, etc.; to weaken in spirit or efficiency. [ 1913 Webster ]

The demoralizing example of profligate power and prosperous crime. Walsh. [ 1913 Webster ]

The vices of the nobility had demoralized the army. Bancroft. [ 1913 Webster ]